A. Field of Invention
This invention relates to hand-held and operated tools such as to routers, jigsaws, spindle sanders, etc., and in particular to an improved mechanism and method for operably mounting such tools upside down into a tabletop or bench but allowing quick and easy removal for hand-held use.
B. Problems in the Art
Hand-held router tools are available in many sizes and designs. Various horsepower electric motors are encased in a housing to which handles are attached for holding and guiding the tool. A collet extending vertically and attached directly to the motor shaft allows exchange and securement of multiple profiles and shank diameters of cutting bits. Surrounding the collet and cutter is a base with a center opening sized to allow clearance for the cutter. The base is attached to the router housing through posts or by sleeving to the outside of the housing. Many hand-held routers have what is called a factory sub-base plate (e.g. a relatively thin plastic ring) of closely or identical diameter and shape as base 14, and attached to base 14 by machine screws. The factory sub-base (not shown) is usually of a material that does not have propensity to make scratches as the router is moved across a surface. It also acts as a sort of wear plate.
These types of routers are intended to be used hand-held, with the factory base/sub-base bearing against a workpiece and the cutter extending downward generally vertical in relation to the workpiece. The worker must move the router relative to the workpiece. This requires good coordination and control on the part of the worker to move the router in the desired manner.
Inverting the router position, with collet and cutter extending vertically up through a corresponding hole in a larger supported surface such as a table, can be advantageous. For example, this allows use of larger cutters, both horizontal and vertical, in relation to base. With cutters extending upward vertically and the router held stationary in a table top, the workpiece is controlled into a rotating cutter or bit, with the router stationary and not moving relative to workpiece. This type of router can sometimes be built-in to a table and therefore is not readily removeable and convertible to hand-held use.
Therefore, attempts have been made to create systems to allow hand held routers to be mountable for table use. The router can then be used in either hand-held or table-mounted mode.
Problems arise with such existing router table designs however. Usually the factory sub-base is removed and a substantial-sized, larger insert plate is mounted by bolts or screws to base of the hand-held router. The hand-held router, with attached insert plate, is inverted and set into a comparable sized receiving opening in a customized table. Phenolic or other plastics are commonly used as the insert plates. The insert plate is usually of a size, which permits the router and router handles to be lowered from the top through the accompanying and size-matching table hole. This can lead to insert plates that sag in the center due to the constant weight applied by the router and the substantial size of the insert plate. These types of plates are also undesirable when using the router in hand-held mode. The size (usually substantially larger than the hand-held router base) and/or shape (many times square or rectangular) obstructs free turning and positioning of the router in hand-held mode, when following templates or straight guides, or when working in limited access areas and, at a minimum, is quite different from the factory base and factory sub-base, and thus makes it difficult to use the router for all its factory capabilities. If a worker is restricted to one router, switching from table use to hand use leaves either an unwieldy added insert plate, or requires time consuming changing of the insert plate to the factory base or base-plate of the router. Therefore, there is room for improvement in the art relative to table support of hand-held routers.
For example, refer to FIGS. 1 and 2. An existing method of converting a hand-held portable router 10 into a table-mounted tool is illustrated. Conventional hand-held routers 10 have a housing 12 encasing a motor, a base plate or plates 14 attached to housing 12 by posts or sleeves 21, handles 16, and a bit 18 removeably positionable in a bit collet or chuck 17 which is rotatable by the electric motor and extendable through opening 19 in base plate 14. An electrical cord 11 supplies connection to an electrical power source.
As illustrated in FIGS. 1 and 2, one state of the art way of converting the hand-held router 10 to a table top tool is to configure a table 20 (see FIG. 2) to include a relatively large rectangular opening 26 with a flange or ridge 28 smaller in perimeter dimensions than opening 26.
A relatively large plate 22 having an opening 23 for bit 18 is mounted by bolts or screws 24 to base plate 14 of router 10 (usually after removal of a factory sub-base). Plate 22 has an outside perimeter which mates into receiving opening 26. Flange 28 supports plate 22. Note that router 10 and plate 22 are inverted and pass into and through opening 26 when mounted into position, so that plate 22 is flush with table top 20. (See FIG. 2).
Once inserted into table 20, cord 11 is connected to appropriate circuitry for access to electrical power, and what was the hand-held portable router 10 now functions as a table mounted tool with bit 18 extendable above the surface of table 20. As can be appreciated, plate 22 sits flush in table 20, to the extent possible. Also, as can be appreciated, fences can be adjustably positioned on tabletop 20 to assist the woodworker when manipulating work pieces to bit 18.
As previously mentioned, the size of plate 22 is usually sufficiently large to support router 10, but also allow handles 16 and housing 12 to pass through table surface 20 when mounting it, and also pass back through when removing router 10 with attached plate 22. Thus, the size and dimensions of such plates 22 are substantially larger than the factory base 14 and factory sub-base, and many times are square or rectangular which is much different than round, and not very conducive to hand-held routing.
This combination makes it very cumbersome and even difficult to then use router 10 in a hand-held portable mode because of the substantial size of plate 22 and many times because of the non-round shape. Removal of plate 22, to convert router 10 back to hand-held mode (and reattachment of factory sub-base), is time consuming and cumbersome, but may be necessary for accurate use of router 10 in a hand-held mode.
Router fences of various designs are often used to set depth of cut and/or add stability to the workpiece. Normally, such fences attach to or across a substantial part of the tabletop and are moveable from very near to the bit to a position away from and towards or near the edge of the tabletop. With the design of FIGS. 1 and 2, removal of the fence is necessary for most cutter bit changes, and for removal of the router from the table.
A mechanism and method is needed allowing a router of almost any size or design to be quickly and easily exchanged from the top of a table, with no fence removal, ready for hand held use with a base plate of generally the same design and feel as its factory base plate.
The same or similar problems exist for many other hand-held tools. Examples are jigsaws, drills, spiral saws, spindle sanders, or other tools having a working member extending downwardly or generally vertically through an integral base plate when in a hand-held and operated mode.
The present invention relates to an apparatus which fits into the top of an existing table, or becomes a self contained table allowing hand-held routers or other tools of a variety of sizes, designs and horsepower to be quickly installed or removed from the table or table top allowing use of the tool in an inverted table-mounted position, with working bit above table surface and the tool stationary relative to the table top surface. Removed, the tool can be used, losing no factory functions, and is not limited by an undesirable and often unusable enlarged base-plate.
A frame includes a receiver into which can be placed and supported the inverted tool, for example, by its factory base, factory sub-base, or substitute sub-base plate. Thus, the advantages of being able to convert the hand-held tool into a table mount tool is provided, with the advantage that when needed as a hand-held portable tool, the limitations and disadvantages of having a substantial sized plate, such as plate 22 of FIGS. 1 and 2, is avoided.
The frame can either be a separate apparatus insertable into a table (such as substantial opening 26 of FIG. 2) or can be built into a table.
In some embodiments, the invention utilizes a relatively small substitute sub-base plate, which is removeably attachable to the tool (in place of the factory sub-base plate) and is not much larger or different in perimeter dimensions than the factory base-plate of the tool.
Additionally, a cover piece can be adapted to overlay the tool, when in inverted table-mounted position in the frame, to help hold the inverted tool in place and provide a smooth top surface for matching the surface of the table. The cover piece can be a separate piece or hingeable or pivotable down over the inverted tool when placed into the frame.